For these requirements in particular, pneumatics represent a cost-effective and reliable alternative to electrical automation systems.

Clean water on the Bosporus (above): Festo automated water works in Istanbul. (Photo: Festo)

Why use pneumatics in water technology? Pneumatic automation technology reduces investment, installation and operating costs compared with electrical installations by over 50% in some cases. Pneumatic drives require no maintenance for their entire lifespan. As process valves are operated irregularly in water technology, deposits or caking can form which lead to much higher breakaway torques. The overload protection of the pneumatics is a crucial feature here.

If the drive comes to a stop, the pressure on the pressure regulator can simply be increased to make it possible to apply more force – avoiding the need for costly maintenance. Another advantage is that the compressed air is available even in the event of an electrical power failure, as an air reservoir is always available as well as a compressor to generate and supply compressed air.

Systematically automated
The valve terminal is at the core of pneumatic systems in water technology as a decentralized element. Near the process valves, it is ideal for rapid and simple automation solutions in which process valves, pneumatics and electronics interact optimally.


Everything in view: modern control cabinets with front-end display, integrated front-end controllers and monitoring software from Festo replaced old control centres.
(Photo: Festo)

The valve terminals are modularly equipped depending on the number of process valves. With the fieldbus, this system solution has just a single, clearly defined and standardized interface between the controller (PLC) and the valve terminal. The advantage of the system concept is that extensions or changes can be made at the control level without replacing the hardware. In addition, all components of the machine technology are compatible. Pneumatics from Festo are used around the world in water works and water purification plants, for example in the Black Forest in Germany and in sunny Greece.

Potable water supply in Istanbul
Although almost entirely surrounded by water, it is no easy task for the Istanbul water supply company ISKI to provide drinking water for the 14 million inhabitants along the straits between Europe and Asia. This requires over 2,000,000 m³ of processed river and rain water every day. To meet the continually rising demand in this boomtown on the Bosporus, ISKI has modernized four processing plants using products from Festo.


2,000,000 m³ of processed river and rain water for 14 million inhabitants daily: new pneumatic drives and positioners from Festo for butterfly valves on the filter basins and control loops with flow and level sensors. (Photo: Festo).

In its extensive product range for water technology, Festo, with its roots in factory automation, offers process automation solutions from process valves to the coordinating level as a complete package: pneumatic drives for hand lever valves, butterfly valves and ball valves, local controllers, control cabinets with valve terminals, integrated controllers and fieldbus.

ISKI replaced the butterfly valves on the filter basins with pneumatic drives and positioners from Festo and installed control loops with flow and level sensors. Modern control cabinets with front-end display, integrated front-end controllers and monitoring software from Festo replaced old control centres.


Automated potable water purification and wastewater treatment helps to ensure a high level of supply and process safety. (Photo: Festo)

Automation with pneumatics makes the operation and maintenance of plants simple and cost-effective. The water quality has improved measurably as a result. Automation enables rapid intervention in the event of an emergency.

Central wastewater treatment plant in Athens
Psyttalia Wastewater Treatment Plant is the name of the ambitious project on the eponymous island of Psyttalia in the bay off the coast of Athens and the harbor town of Piraeus. Sewage is pumped through pipelines 1.5 km long from the mainland to the rocky island of Psyttalia. The technical data underlines the gigantic scale of the plant: the biological purification process includes 12 fermentation tanks with a total volume of almost 300,000 m³ and a flow rate of 1,000,000 m³ per day.


Psyttalia Wastewater Treatment Plant: the waste water from Athens is pumped along a 1.5 km pipeline from the mainland to the purification plant on the rocky island of Psyttalia.
(Photo: Festo)

Inflow is controlled by gate valves with pneumatic linear drive units of the Festo type DLP. These act directly on the slide gate and so require no maintenance, unlike other types of drive. The flow control system for the biogas generated in the fermentation tanks uses semi-rotary drives. They also regulate the distribution of hot water for the heat exchangers, which maintain a constant temperature of 36°C in the fermentation tanks. 
http://www.festo.ca/